Implant bleeding or AF

Shanice

Had my last period 9/6-9/12 last day I had sex was 9/22. Started bleeding today at work 10/11 put on a bad had a little dark blood and then as the day went on it is getting lighter. Having some cramps and had sec last night had to stop because I got a pain on my side like towards my belly button. Does this sound more like AF or could implant bleeding be this many days after ovulation new to this stuff.